This invention relates to acetylene-terminated oligomeric and polymeric compositions and to a method for facilitating and improving the processing of such compositions. In a more particular aspect, this invention relates to additive materials for use in aiding and improving the processing characteristics of acetylene-terminated oligomers and polymers.
At the present time, considerable interest has evolved in the development of polymeric materials characterized by high strength and elevated temperature stability. Materials which possess these characteristics are especially useful as matrix resins in the fabrication of structural composites and molded components; as high strength adhesives for structurally bonded joints; and as laminating resins in the production of high strength laminates. Among the materials found to possess these desired properties are acetylene-terminated oligomers and polymers. Unfortunately, these polymers are difficult to process and the resulting processed products do not possess the degree of toughness required to withstand the severe stresses and strains which exist within the operational environment of present day aerospace vehicles and systems.
In an attempt to overcome the problems encountered heretofore in using acetylene-terminated oligomers and polymers, it was found that the use of hydroxy-substituted polynuclear, aromatic derivatives as cure retarding additives for the polymers provided an easy processing, highly mobile (low viscosity melt) polymer with an enhanced performance capability when used in adhesive, matrix, or laminating applications. The unexpected increase in performance capability of the polymers of this invention is attributed to the fact that the resins possess improved melting characteristics and a broader processing tolerance. Also, the additives allow for a controlled cross-link density, thus providing a means for formulating a tougher and more fracture resistant polymeric material.